Single-cell battery, battery module, power battery, and electric vehicle

ABSTRACT

The present disclosure is directed to a single-cell battery, a battery module, a power battery, and an electric vehicle. The single-cell battery includes a case, a battery cell accommodated in the case, an electrode terminal electrically connected to the battery cell, and a cover plate for sealing the case. The electrode terminal is disposed on the cover plate. The electrode terminal includes a battery post passing through the cover plate and electrically connected to the battery cell. The single-cell battery further includes a current interruption device mounted on the battery post. The current interruption device is in communication with gas inside the case. The current interruption device has a conductive member and a flipping member connected to the conductive member for mutual electrical connection. The flipping member and the conductive member are electrically disconnected from each other under action of air pressure. The conductive member is connected to the battery post for mutual electrical connection.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of InternationalApplication No. PCT/CN2016/097402, filed on Aug. 30, 2016, which isbased on and claims priority to and benefits of Chinese PatentApplication Nos. 201610105569.3 and 201620142798.8, both filed with theState Intellectual Property Office (SIPO) of the People's Republic Chinaon Feb. 25, 2016. The entire contents of the above-identifiedapplications are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the field of batteries, and inparticular, to a single-cell battery, a battery module including thesingle-cell battery, a power battery including the battery module, andan electric vehicle including the power battery.

BACKGROUND

As energy storage units, batteries play an important role in variousindustries. For example, power batteries are widely applied in fieldssuch as new energy vehicles. In a battery pack of a power battery,multiple single-cell batteries may be connected in series or in parallelto form a battery module, to implement a charge/discharge operation. Thepower battery usually uses a battery management system (BMS) to monitora voltage change and a current change and calculate a state of charge inthe charge/discharge process. However, a voltage sampling failure maylead to overcharging of the battery. Particularly, in a ternary system,there is a danger of battery burning or explosion if the overchargingreaches a certain amount.

In the existing technical solution, during monitoring of a batteryvoltage and current, a current integration method and an open circuitvoltage method are used to calculate a battery level, to control batterycharge/discharge management. However, there are disadvantages. Forexample, because of a battery voltage sampling failure, a batterycurrent sampling failure, or a software failure, a battery is rechargedfor a long time and out of control. Particularly, in a case ofrecharging by using a charging pile, overcharging cannot be controlledif the charging pile fails to communicate with a battery manager, andwhen the overcharging reaches a certain amount, battery swelling andeven explosions or fires are caused.

Therefore, it is of positive significance to provide a currentinterruption technology for proactively and forcibly interrupting acurrent.

SUMMARY

An objective of the present disclosure is to provide a single-cellbattery. The single-cell battery can forcibly interrupt a current whenin an emergency state, thereby preventing a danger such as a batteryexplosion from occurring.

The objective of the present disclosure is to further provide a batterymodule using the single-cell battery, a power battery using the batterymodule, and an electric vehicle using the power battery.

To achieve the foregoing objectives, the present disclosure provides asingle-cell battery. The single-cell battery includes a case, a batterycell accommodated in the case, an electrode terminal electricallyconnected to the battery cell, and a cover plate for sealing the case.The electrode terminal is disposed on the cover plate. The electrodeterminal includes a battery post passing through the cover plate andelectrically connected to the battery cell. The single-cell batteryfurther includes a current interruption device mounted on the batterypost. The current interruption device is in communication with gasinside the case. The current interruption device has a conductive memberand a flipping member connected to the conductive member for mutualelectrical connection. The flipping member and the conductive member canbe electrically disconnected from each other under action of airpressure. The conductive member is connected to the battery post formutual electrical connection. The flipping member and the conductivemember are connected to each other by using a boss welded structure. Theboss welded structure includes a boss, a connection hole accommodatingthe boss, and an annular welding spot located between the boss and theconnection hole. The flipping member is formed in a first sheet-likestructure. The first sheet-like structure is provided with theconnection hole. The conductive member is formed in a second sheet-likestructure. The second sheet-like structure is provided with the boss.The conductive member is connected to an outer end surface of thebattery post. An outer periphery of the flipping member is fixedrelative to the cover plate. The battery post is mounted in a ceramicring tightly connected to the cover plate and is insulated from theouter periphery of the flipping member by using the ceramic ring.

Optionally, the flipping member and the conductive member are connectedto each other by using a boss welded structure. The boss weldedstructure includes a boss, a connection hole accommodating the boss, andan annular welding spot located between the boss and the connectionhole.

Optionally, the flipping member is formed in a first sheet-likestructure, the first sheet-like structure is provided with theconnection hole, the conductive member is formed in a second sheet-likestructure, and the second sheet-like structure is provided with theboss.

Optionally, the conductive member is provided with a notch, and thenotch is disposed surrounding a connection point for connecting to theflipping member.

Optionally, the notch is elliptical, the connection point is a circularconnection point, and a center of the notch and a center of theconnection point are staggered along a direction of major axis of theellipse.

Optionally, the flipping member and the electrode terminal are coaxiallydisposed, and the conductive member is obliquely disposed relative to anaxial line of the electrode terminal.

Optionally, the conductive member is connected to an outer end surfaceof the battery post, and an outer periphery of the flipping member isfixed relative to the cover plate.

Optionally, the outer end surface of the battery post is provided withan accommodation hole, and an outer periphery of the conductive memberis fixed to an inner wall of the accommodation hole.

Optionally, the battery post is mounted in a ceramic ring tightlyconnected to the cover plate.

Optionally, an inner end surface of the ceramic ring is tightlyconnected to a transition ring, and the transition ring is tightlyconnected to the cover plate so that the ceramic ring and the coverplate are disposed at intervals.

The present disclosure further provides a battery module. The batterymodule is provided with the single-cell battery according to the presentdisclosure.

The present disclosure further provides a power battery, including aninclusion body and a battery module disposed inside the inclusion body.The battery module is the battery module according to the presentdisclosure.

The present disclosure further provides an electric vehicle. Theelectric vehicle is provided with the power battery according to thepresent disclosure.

In the foregoing technical solution, a gas may be produced when thebattery is in an emergency case. Therefore, as the air pressureincreases, a flipping member can flip over under action of the airpressure, to disconnect from the conductive member, therebydisconnecting the charge/discharge circuit of the power battery, andfurther avoiding a further increase in the battery air pressure andexplosions. In addition, the boss welded structure ensures stablepassing of a high current, and the ceramic ring improves leak tightness,insulativity, and stability.

Other features and advantages of the present disclosure are to bedescribed in detail in the following part of detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used to provide a further understanding ofthe present disclosure, and constitute a part of the specification,which are used to explain the present disclosure in combination with thefollowing specific implementations, and do not constitute a limitationto the present disclosure. In the accompanying drawings:

FIG. 1 is a partial exploded three-dimensional schematic diagram of apower battery according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural top view of two adjacent single-cellbatteries according to the present disclosure;

FIG. 3 is a schematic structural sectional view along line A-A in FIG.2;

FIG. 4 is an exploded schematic structural diagram of a currentinterruption device according to an embodiment of the presentdisclosure;

FIG. 5 is an exploded schematic structural diagram of a flipping memberand a conductive member according to an embodiment of the presentdisclosure;

FIG. 6 is a schematic structural sectional view of a flipping member anda conductive member in an assembled state according to an embodiment;

FIG. 7 is a schematic structural top view of a conductive memberaccording to an embodiment of the present disclosure;

FIG. 8 is a schematic structural sectional view of a battery post and aceramic ring according to an embodiment of the present disclosure;

FIG. 9 is a three-dimensional schematic structural diagram of thebattery post in FIG. 8;

FIG. 10 is a schematic structural sectional view of a battery post and aceramic ring according to an embodiment of the present disclosure;

FIG. 11 is a three-dimensional schematic structural diagram of thebattery post and the ceramic ring in FIG. 10;

FIG. 12 is a schematic structural diagram of two adjacent single-cellbatteries according to an embodiment of the present disclosure;

FIG. 13 is a three-dimensional schematic structural diagram of a powerbattery according to an embodiment of the present disclosure;

FIG. 14 is a three-dimensional schematic structural diagram of asingle-cell battery according to an embodiment of the presentdisclosure;

FIG. 15 is an exploded three-dimensional schematic structural diagram ofa single-cell battery according to an embodiment;

FIG. 16 is an exploded three-dimensional schematic structural diagram ofa flipping member and a conductive member according to an embodiment;

FIG. 17 is a partial schematic structural sectional view of asingle-cell battery according to an embodiment;

FIG. 18 is a partial schematic structural sectional view of asingle-cell battery according to an embodiment of the presentdisclosure;

FIG. 19 is a principle block diagram of a control system according to anembodiment of the present disclosure;

FIG. 20 is an exploded schematic structural diagram of a single-cellbattery according to an embodiment of the present disclosure;

FIG. 21 is a partial schematic structural sectional view of thesingle-cell battery in FIG. 20 after assembling;

FIG. 22 is a partial schematic structural sectional view of asingle-cell battery according to an embodiment of the presentdisclosure;

FIG. 23 is a schematic structural diagram of a current interruptiondevice according to an embodiment of the present disclosure; and

FIG. 24 is a partial schematic structural sectional view of asingle-cell battery according to an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

The following describes in detail specific embodiments of the presentdisclosure with reference to the accompanying drawings. It should beunderstood that the specific embodiments herein are used merely fordescribing the present disclosure and are not intended to limit thepresent disclosure.

Unless otherwise specified, nouns of locations such as “up, down, left,and right” used in the present disclosure are generally defined based onfigure plane directions of corresponding accompanying drawings, and“inside and outside” refers to an inner part and an outer part of acorresponding component.

The present disclosure provides technical solutions of a currentinterruption device, a single-cell battery, a battery module, a powerbattery, and an electric vehicle. The current interruption device isdisposed inside the single-cell battery. Multiple single-cell batteriesare connected in series or in parallel to form the battery module andmay be placed inside a battery pack to form the power battery. Moreover,in addition to the field of power batteries, various technical solutionsprovided in the present disclosure may be further widely applied toother battery fields. Specifically, the present disclosure relates tosingle-cell batteries 100, 1100, 2100, 3100, and 4100, and relates tocurrent interruption devices 200, 1200, 3200, 4200, and an explosionrelief valve 2200. In addition, the present disclosure further relatesto a charge/discharge protection system having the power battery. Thefollowing describes the embodiments in detail with reference to theaccompanying drawings.

The present disclosure provides a battery module, including the multiplesingle-cell batteries 100, 1100, 2100, 3100, and 4100. The single-cellbattery may include a case, a battery cell accommodated in the case,electrode terminals 101, 1101, 2101, 3101, and 4101 electricallyconnected to the battery cell, and cover plates 102, 1102, 2102, 3102,and 4102 for sealing the case. The electrode terminal is disposed on thecover plate, to input and output currents. The single-cell batteryincludes the current interruption devices 200, 1200, 3200, and 4200 orthe explosion relief valve 2200. The current interruption device or theexplosion relief valve is electrically connected to the electrodeterminal. Therefore, input and output of currents on the electrodeterminal can be controlled under action of the current interruptiondevice. That is, for the current interruption device or the explosionrelief valve in the single-cell battery is normally connected to thebattery cell. In this case, the electrode terminal can normally inputand output currents, to complete a charge/discharge operation of thesingle-cell battery. However, in an emergency state, for example, whenthe battery is overcharged, the current interruption device or theexplosion relief valve may stop the current input and output of theelectrode terminal, to prevent the battery from being recharged at anexcessive rate. Therefore, reliability of the current interruptiondevice is crucial as an important safety measure. That is, the currentinterruption device needs to be capable of making a quick response.Moreover, the current interruption device or the explosion relief valvemay alternatively be fixed relative to the cover plate. That is, thecurrent interruption device or the explosion relief valve may bedirectly fixed to the cover plate, or may be fixed to any componentconnected to the cover plate or fixed relative to the cover plate. Forexample, the current interruption device or the explosion relief valveis mounted on the electrode terminal in the cover plate.

In the present disclosure, the current interruption device or theexplosion relief valve each is a mechanical structure for sensing theair pressure. Specifically, the current interruption device is incommunication with gas inside the case of the single-cell battery, andcan interrupt, under action of the air pressure, a current passingthrough the current interruption device. Specifically, connectionsbetween internal components may be disconnected to stop currenttransmission, thereby stopping charging/discharging of the battery in atimely manner. A source of the air pressure used is: for example, whenan emergency case such as overcharging of the battery occurs, a gas isproduced inside the battery, then leading to an increase in the airpressure inside the case, or an exception occurs in the battery duringuse, causing an increase in the temperature of the battery and anincrease in the air pressure inside the battery, thereby generating airpressure power for driving the current interruption device or theexplosion relief valve.

FIG. 1 to FIG. 12 provide some embodiments. As shown in FIG. 3 to FIG.6, FIG. 8, and FIG. 10, the current interruption device 200 has aconductive member 201 and a flipping member 202 electrically connectedto the conductive member 201. The flipping member 202 and the conductivemember 201 can be electrically disconnected from each other under actionof air pressure. In the present disclosure, electrical disconnection maybe implemented in different manners. A connection point between may bedisconnected. For example, a welding spot between the conductive memberand the flipping member is removed to implement the electricaldisconnection. Alternatively, at least one of the conductive member andthe flipping member is broken. For example, a weakening notch is made ina corresponding component to implement disconnection of a structure,thereby implementing the electrical disconnection. That is, an objectiveof stopping current transmission by disconnecting a mechanical structureunder action of the air pressure is achieved in the present disclosure.

In this way, for example, when the battery is overcharged, a gap isproduced inside the battery and then the air pressure increases. In thiscase, the flipping member 202 is disconnected from the conductive member201 by performing a flipping action, so that a circuit between theelectrode terminal 101 and the outside is disconnected, and charging ofthe battery is stopped, thereby avoiding a further increase in the airpressure inside the battery, and ensuring battery safety.

The electrode terminal 101 includes a battery post 104 electricallyconnected to the battery cell. For example, the battery post 104 isconnected to the battery cell by using an internal guide member. Thebattery post 104 passes through the cover plate 102 to guide a currentfrom the case. The current interruption device 200 is mounted on thebattery post 104. In this way, the air pressure inside the battery maybe detected by using the battery post 104, so that the sensitivity ishigh. Moreover, the current interruption device 200 does not need to beconnected to the electrode terminal additionally, thereby facilitatingprocessing.

In a field such as the field of power batteries, a high current needs topass. Therefore, stability of a welded structure of the conductivemember 201 and the flipping member 202 needs to be ensured, to preventthe high current from breaking the welded structure. In this way, in anembodiment, as shown in FIG. 5 and FIG. 6, the flipping member 202 andthe conductive member 201 are connected to each other by using a bosswelded structure. The boss welded structure includes a boss 203, aconnection hole 204 accommodating the boss 203, and an annular weldingspot 217 located between the boss 203 and the connection hole 204.Therefore, it can be ensured that the annular welding spot 217 is usedto firmly weld the boss 203 accommodated in the connection hole 204, anda passing area of the current can be increased to ensure passing of thehigh current. Specifically, the boss 203 is formed in the conductivemember 201, and the connection hole 204 is formed in the flipping member202. More specifically, the flipping member 202 is formed in a firstsheet-like structure, the first sheet-like structure is provided withthe connection hole 204, the conductive member 201 is formed in a secondsheet-like structure, and the second sheet-like structure is providedwith the boss 203. In another embodiment, alternatively, the boss 203may be disposed on the flipping member 202, and the connection hole 204is disposed in the conductive member 201. Moreover, in some embodiments,the flipping member 202 and the conductive member 201 may bealternatively welded together by using a laser penetration weldingmanner, or the like.

The flipping member and the conductive member may be electricallydisconnected from each other by using a notch. That is, a weakeningportion with strength less than that of a weakening portion in anotherregion is provided in a corresponding part. In order that the conductivemember and the flipping member are completely disconnected from eachother, the notch is usually an annular structure surrounding aconnection point between the conductive member and the flipping member,for example, the boss welded structure. In this way, electricaldisconnection is implemented with disconnection of the conductive memberor the flipping member. The notch may be formed in the flipping memberor may be formed in the conductive member. In an embodiment, theconductive member 201 is provided with a notch 205. The notch 205 issurrounding a connection point for connecting to the flipping member202. That is, an annular notch is disposed in the conductive member 201and surrounding the boss 203. In this way, when the air pressure insidethe battery increases, the notch 205 may be pulled apart under action ofthe air pressure, so that the part of the boss 203 surrounded by thenotch 205 is separated from the conductive member 201 with the flippingmember 202, thereby implementing interruption of the current. In anotherimplementation, alternatively, the notch may be formed in the flippingmember 202.

As shown in FIG. 7, to help pulling the notch 205 apart, preferably, thenotch 205 is elliptical. In this way, under action of the air pressure,because of different contour curvature, stress is more easilyconcentrated in a region with a greater curvature and the received forceis strong. In this way, such a region can be first torn, therebyincreasing sensitivity in pulling the notch 205 apart. Further, in thisembodiment, the boss 203 is circular, and a center of the ellipticalnotch 205 and a center of the boss 203 are staggered a long a directionof major axis of the ellipse. In this way, regions at two ends of themajor axis of the ellipse may receive uneven force, so that the notch205 is easily pulled apart at a local point, thereby improvingsensitivity of the notch 205.

Moreover, the flipping member 202 and the electrode terminal 101 may becoaxially disposed, and the conductive member 201 is obliquely disposedrelative to an axial line of the electrode terminal 101. In this way, anotch at a lower location may be first pulled apart, thereby increasingsensitivity in pulling the notch 205 apart. Further, when the notch 205is elliptical, in a design, the major axis of the ellipse and the axialline of the conductive member are obliquely disposed. When theconductive member is mounted on the battery post, the conductive memberand an axial line of the battery post are also obliquely disposed. Inthis way, a region with greater curvature on an end portion of the majoraxis is first and easily torn, thereby ensuring that the notch 205 canbe normally pulled apart when needed, and ensuring normal operation ofthe current interruption device 200.

Moreover, to further ensuring that the notch 205 is pulled apart,alternatively, as shown in FIG. 7, in a design, the notch 205 isprovided with a weakening hole 206. In this way, the notch 205 is easilypulled apart at a location of the weakening hole 206. A size of theweakening hole 206 and a quantity of weakening holes 206 may be setaccording to an actual situation. Preferably, there are multipleweakening holes 206 disposed at intervals along the notch 205. Inaddition to the effect of weakening, when the notch is designed in theconductive member 201, the weakening hole 206 may be further used forair guiding, so that the gas inside the battery can apply the airpressure to the flipping member 202 by using the weakening hole 206.

As shown in FIG. 3, FIG. 8, and FIG. 10, when the current interruptiondevice 200 is mounted on the battery posts 104, 104′, and 104″, theconductive member 201 is connected to outer end surfaces of the batteryposts 104, 104′, and 104″, and an outer periphery of the flipping member202 is fixed relative to the cover plate 102. In this way, under actionof air pressure, the outer periphery of the flipping member 202 is usedas a support point, and the notch 205 formed in the conductive member201 can be pulled apart. Moreover, to enable the flipping member 202 tobe under action of the air pressure, the outer periphery of the flippingmember may be sealed, for example, may be tightly connected to the coverplate with welding, to that the internal air pressure can apply force tothe flipping member to pull the notch 205 apart. Herein and in similardescriptions, an outer end or an inner end is defined relative to thecase along an axial direction of the battery post, and the “inside andoutside” relative to an annular member, for example, the outerperiphery, is defined relative to a center of the annular member alongthe radial direction.

To ensure that the notch 205 in the conductive member 201 can still bepulled apart when the conductive member 201 and the battery post 104′are fixed, preferably, the outer end surface of the battery post 104 isprovided with an accommodation hole 218, and an outer periphery of theconductive member 201 is fixed to an inner wall of the accommodationhole. In this way, the conductive member 201 may be stably fixed at theannular periphery, while a region inside the notch 205 can be pulledapart under action of external force such as tensile force of theflipping member 202 or the direct pressure of the gas because the regioninside the notch 205 is not connected to the battery post 104.

In the present disclosure, the current interruption device may be incommunication with gas inside the battery in multiple manners. Thebattery posts 104 and 104′ are each provided with an air-guide ductcommunicating an inner part of the case and the current interruptiondevice 200. In this way, air pressure is applied to the currentinterruption device by directly using internal structures of the batteryposts 104 and 104′. Therefore, the structure is more simple.

In an embodiment shown in FIG. 8 and FIG. 9, the air-guide duct includestwo types of air-guide holes 103. A first-type air-guide hole 103 isused to communicate the accommodation hole 218 and an inner part of thecase, that is, directly apply pressure to the conductive member 201 topunch the notch 205 apart. That is, the air-guide duct includes theair-guide hole 103 for communicating the accommodation hole 218 and theinner part of the case. A second-type air-guide hole 103 is used tocommunicate the flipping member 202 and the inner part of the case, toapply pressure to the flipping member to pull the notch 205 apart. Toimprove stress distribution efficiency of the flipping member 202, thereare multiple such type of air-guide holes 103 surrounding theaccommodation hole. Therefore, under joint action of the two types ofair-guide holes 103, sensitivity of the current interruption device canbe improved.

Specifically, as shown in FIG. 8, the battery post 104′ is fixedlyconnected to the cover plate 102, so that the structure of the electrodeterminal is stable. An outer end periphery of the battery post 104′ hasa radial boss 105, the radial boss 105 fixedly connected to the coverplate 102, and the second-type air-guide hole 103 is formed in theradial boss 105, so that gas flows to the flipping member 202. Thefirst-type air-guide holes 103 are formed inside the battery post 104′along an axial direction. That is, the air-guide hole 103 located in theradial boss 105 is used to apply pressure to the flipping member 202,while the air-guide hole 103 below the accommodation hole 218 maydirectly apply pressure to the conductive member 201. As shown in FIG.9, in this embodiment of the present disclosure, the radial boss 105 ofthe battery post 104′ and a body of the battery post are both providedwith the air-guide hole 103. The first-type air-guide holes 103 in thebody of the battery post is in communication with the accommodation hole218 in the end surface, and there are four first-type air-guide holes103 which are disposed at equal intervals along a circumferentialdirection. In another embodiment, alternatively, there may be anotherquantity of first-type air-guide holes 103. The quantity of thefirst-type-guide holes is not limited in the present disclosure.

As shown in FIG. 3, FIG. 8, and FIG. 10, to prevent the cover plate frombeing electrified, preferably, the battery posts 104, 104′, and 104″need to be insulated from the cover plate when fixedly connected to thecover plate. Therefore, the battery posts 104, 104′, and 104″ arefixedly connected to ceramic rings 207 and 207′ tightly connected to thecover plate 102, for example, with ceramic brazing. This achieves higherreliability and weather resistance than insulation implemented by usingplastics or rubber, and not only stable and tight connection of thecurrent interruption device can be implemented, but also insulationbetween the battery posts and the cover plate can be implemented.Specifically, outer end peripheries of the battery posts 104, 104′, and104″ have the radial bosses 105 and 105′, and inner edges of the ceramicrings 207 and 207′ have radial supports 208 and 208′ supporting andconnected to the radial bosses 105 and 105′. The radial bosses 105 and105′ are embedded in the ceramic rings 207 and 207′ and are connected tothe radial supports 208 and 208′. That is, the radial supports 208 and208′ are relatively thin to form a staircase-type accommodation space inwhich the battery posts 104, 104′, and 104″ are embedded.

In the embodiment shown in FIG. 11, different from the foregoing gasrelease manner in which the battery post is provided with the air-guidehole 103, there are multiple radial bosses 105′ and multiple radialsupports 208′ disposed at intervals along the circumferential direction.That is, there are multiple radial bosses 105′ disposed at intervalsalong the circumferential direction, and there are multiple radialsupports 208′ disposed at intervals along the circumferential direction.In addition, the multiple radial bosses are in a one-to-onecorrespondence with the multiple radial supports. In this way, gasrelease may be implemented by using spacing between adjacent radialbosses 105′ and spacing between the radial supports 208′. The structureis simpler and more ingenious, the processing is easy, and the batterypost 104″ does not need to be additionally provided with any air-guideduct. Therefore, a region on the battery post 104″ for assembling theconductive member 201 is not affected. In addition, a size of theconductive member 201 may be maximized, to increase a size of the notchand ensure sensitivity in pulling apart the notch. In this embodiment,there are three radial bosses 105′ disposed at equal intervals, toensure both connection stability and air permeability. In anotherembodiment, there may be another quantity of radial bosses, for example,four or more radial bosses.

Outer end surfaces of the ceramic rings 207 and 207′ are each formed ina stepped structure having an inner ring and an outer ring. The batteryposts 104, 104′, and 104″ are in embedded connection with the innerrings. A difference lies in that in an embodiment of a one-piece radialboss 105, the inner ring is formed in an integral annular radialsupport, while in an embodiment of a separable radial boss 105′, theinner ring is formed as the foregoing multiple disposed at intervalsradial supports 208′, thereby making the overall structure more compactand the connection more stable.

In the foregoing embodiment, to establish a current flowing path to theoutside, preferably, the outer end surfaces of the ceramic rings 207 and207′ are tightly connected to the conductive ring 216, and arespecifically connected to the outer ring. The outer periphery of theflipping member 202 is fixedly connected to the conductive ring 216.That is, the flipping member 202 is connected to the ceramic rings 207and 207′ by using the conductive ring. The conductive ring may establisha current loop between the flipping member and the outside. To preventthe conductive ring from being still electrically connected to thebattery post after the notch is pulled apart, and invalidating thefunction of the current interrupt, preferably, the conductive ring 216is tightly connected to the outer ring of the ceramic ring to beinsulated from the battery post. In other words, the battery posts 104,104′, and 104″ are insulated from the conductive ring 216 by using theceramic ring. Moreover, the conductive ring 216 is tightly connected tothe ceramic ring so that the outer periphery of the flipping member canbe sealed, and the air pressure inside the case can act on the flippingmember without leakage.

To implement stable connection between the conductive ring and theflipping member, an outer end surface of the conductive ring 216 isprovided with an L-shaped rabbet, and an inner end surface of theconductive ring 216 is used for connecting to the outer ring of theceramic ring. The outer periphery of the flipping member 202 is embeddedin and supports the L-shaped rabbet. In addition, the outer periphery istightly connected to the L-shaped rabbet by using a covering cap 210covering the flipping member 202. Therefore, the current interruptiondevice 200 can be protected while stable sealing and assembling of theflipping member 202 are implemented. Moreover, the conductive ring 216may establish a current loop to the outside world by connecting to thecovering cap or by using electrode guide pieces directly connected toeach other. For example, adjacent single-cell batteries 100 or adjacentbattery modules may be connected to each other by using electrode guidepieces.

In order that the ceramic rings 207 and 207′ are easily and tightlyconnected to the cover plate 102, preferably, inner end surfaces of theceramic rings 207 and 207′ are tightly connected to the transition ring209. The transition ring 209 may be connected to the ceramic rings 207and 207′ with ceramic brazing. In addition, the transition ring 209 istightly connected to the cover plate 102. The transition ring 209 mayfurther be used so that the ceramic rings 207 and 207′ and the coverplate 102 are disposed at intervals. Because the ceramic rings 207 and207′ are not directly assembled with the cover plate 102, the coverplate 102 can be protected from high temperature caused during brazingof the ceramic ring. Moreover, areas of the ceramic rings 207 and 207′are not limited by a need of being directly assembled with the coverplate 102. In addition, no specific design is required for the ceramicrings 207 and 207′, so that manufacturing and assembling are convenient.

As shown in FIG. 3, FIG. 8, and FIG. 10, preferably, the transition ring209 has an inner ring and an outer ring that form a Z-shaped structure.The cover plate 102 is provided with a through hole through which thebattery posts 104, 104′, and 104″ pass. An end surface of the throughhole is in a staircase structure. The inner ring of the transition ringis embedded in and supports the staircase structure. That is, in FIG. 3,FIG. 8 and FIG. 10, the inner ring is located at the bottom and is inembedded into the through hole, thereby increasing a contact area of thetwo and ensuring connection stability.

Therefore, in the foregoing embodiment, to implement the currentinterruption device 200, the outer periphery of the flipping member 202needs to be sealed. Specifically, the ceramic rings 207 and 207′ aretightly connected between the outer periphery of the flipping member andthe cover plate, thereby implementing stable and reliable operation ofthe current interruption device by using a ceramic sealing structure. Insuch a ceramic sealing structure, tight connections between the coverplate and the transition ring, between the transition ring and theceramic ring, between the ceramic ring and the conductive ring, andbetween the conductive ring and the flipping member enable the airpressure inside the case to effectively act on the current interruptiondevice, so that the operation of the current interruption device isreliable. During assembling, to ensure leak tightness of the currentinterruption device, the ceramic rings 207 and 207′ are separately andtightly connected to the conductive ring 216, the battery posts 104,104′, and 104″, and the transition ring 209 with ceramic brazing. Thatis, the conductive ring 216, the battery posts 104, 104′, and 104″, andthe transition ring 209 first form an independent assembly, and then thetransition ring 209 is assembled to the cover plate 102 with laserwelding. The assembling manner is convenient and the ceramic ring doesnot need to be welded to the cover plate with brazing. Moreover, theconductive member 201 may be connected to the battery posts 104, 104′,and 104″ with laser welding. The flipping member and the conductivemember may be connected to each other with laser penetration welding orby using the foregoing boss welded structure, or in another manner. Thecovering cap 210 and the conductive ring may be connected to each otherwith laser welding. In addition, the battery posts 104, 104′, and 104″and a guide piece of the battery cell may be welded together with laserwelding, to complete the overall assembly of the current interruptiondevice.

The structure of the current interruption device 200 is mainly describedabove. The following describes a disposition manner of the currentinterruption device 200.

To ensure normal and timely operation of the foregoing airpressure-driven current interruption device 200, a size of the currentinterruption device 200 may be designed relatively large. In this way,if air pressure cannot be changed, pulling strength can be increased byincreasing a force receiving area. For example, an area of the flippingmember is designed relatively large to increased pulling strength of theflipping member. In the embodiment shown in FIG. 1, the currentinterruption device 200 is designed to extend out of the cover plate 102along the radial direction, to increase the size. In this case, in thebattery module, there are multiple single-cell batteries 100. To preventthe current interruption device 200 extending outwards from affecting anelectrode terminal in adjacent single-cell batteries 100, preferably,between the adjacent single-cell batteries 100, the current interruptiondevice 200 and an adjacent electrode terminal are staggered in adirection of extension of the cover plate. This can fully use a region,in which no electrode terminal 101 is disposed, on the cover plate 102,so that the protruding current interruption device does not affect astructure in the cover plate, and occupancy of space inside the batterypack can be fully reduce, thereby increasing energy density in theinclusion body. It should be noted that, herein and in the followingdescription of the present disclosure, a meaning of “between theadjacent single-cell batteries”, “between the current interruptiondevice and the adjacent electrode terminal”, or “between adjacentelectrode terminals” refers to connection of adjacent features betweendifferent single-cell batteries, instead of connection of adjacentfeatures in a same single-cell battery.

In this embodiment, the current interruption device 200 and the adjacentelectrode terminal 101 are staggered in the direction of extension ofthe cover plate. In another embodiment, the current interruption device200 and the adjacent electrode terminal 101 may alternatively bestaggered in a height direction.

In an embodiment, as shown in FIG. 1, between the adjacent single-cellbatteries 100, the current interruption device 200 is connected to theadjacent electrode terminal by using an L-shaped connecting member 214.The L-shaped connecting member 214 has a cover portion 211 and a guideportion 212. The cover portion 211 covers and is connected to thecurrent interruption device 200. The guide portion 212 extends to theadjacent electrode terminal, to be adjacent to the electrode terminal.The L-shaped connecting member shown in FIG. 1 is first aligned with theelectrode terminal in the direction of extension of the cover plate, andthen extends to the electrode terminal. In another embodiment,alternatively, the L-shaped connecting member may first extend to anadjacent cover plate, and then extends to the electrode terminal, toimplement electrical connection between the two.

In another embodiment, as shown in FIG. 2, between the adjacentsingle-cell batteries 100, the current interruption device 200 includesa covering cap 210 covering the flipping member 202. The covering cap210 extends along the cover plate 102, to be aligned with the adjacentelectrode terminal, that is, has the cover portion 211 and theintroduction portion 212 that are disposed linearly, and is connected tothe adjacent electrode terminal by using a linear I-type connectingmember 215. The I-type connecting member 215 may be further configuredto connect other electrode terminals 101 between the single-cellbatteries 100 and in which the current interruption device 200 is notdisposed. In this way, with the covering cap 210 in such shape, theentire battery module basically may need only this type of connectingmember.

Different from the embodiment shown in FIG. 2, as shown in FIG. 12,alternatively, the single-cell battery 100 may be enlarged to adapt to arelatively large current interruption device. Specifically, between thesingle-cell batteries 100, a width of a single-cell battery 100 providedwith the current interruption device 200 is greater than a width of thesingle-cell battery not provided with the current interruption device200. In addition, the current interruption device 200 extends close toan edge of the width of the cover plate 102, so that the currentinterruption device 200 can also be adapted to.

Moreover, because the corresponding single-cell battery is wide, thecurrent interruption device can be caused not protrude the cover plate,so that the adjacent electrode terminals can be aligned with each other.This can also avoid impact of the current interruption device 200extending out of the cover plate 102 on a welding structure or anotherstructure of the adjacent cover plate 102. In addition, preferably, thecurrent interruption device and the adjacent electrode terminal can becaused to be connected to each other by using the linear I-typeconnecting member 215.

Moreover, during use, although the width of the single-cell battery 100is increased, a capacity of the battery cell is not increased. That is,a battery cell capacity of the single-cell battery 100 provided with thecurrent interruption device 200 is the same as a battery cell capacityof the single-cell battery 100 not provided with the currentinterruption device. Therefore, existence of single-cell batteries withdifferent capacities in a same module is avoided, thereby avoidingimpact on a BMS. Because of the same battery cell capacity, residualspace inside the case may be filled up by using a partition plate. Thatis, the battery cell is surrounded by the partition plate, so that anassembling structure of the battery cell is stable. Comprehensivelyconsiders the size of the battery module and the size of the single-cellbattery, a ratio of the size of the battery cell to the size of thepartition plate may be 1:1 to 2:1. The partition plate may be made of anelectrolyte resistance material.

Moreover, considering a current interrupt effect, costs, and assembling,in the multiple single-cell batteries 100 in the same module, the numberof single-cell batteries provided with the current interruption device200 needs to be not greater than three. Preferably, the number ofsingle-cell batteries provided with the current interruption device 200is three. Preferably, the single-cell batteries provided with thecurrent interruption device 200 is single-cell batteries located on anend portion and in the central part of the battery module. If thebattery module includes n sequentially arranged single-cell batteries,the single-cell batteries on the end portion of the battery module are afirst single-cell battery of the battery module and an n^(th)single-cell battery of the battery module. When n is an odd number, thesingle-cell battery in the central part of the battery module is the((n+1)/2)^(th) single-cell battery of the battery module. When n is aneven number, the single-cell battery in the central part of the batterymodule is the (n/2)^(th) single-cell battery or the ((n+2)/2)^(th)single-cell battery of the battery module, where n>3.

The current interruption device, the single-cell battery, and thebattery module provided in the embodiments according to FIG. 1 to FIG.12, features such as a boss welded structure, an elliptical notch, and aceramic ring according to the embodiments of FIG. 1 to FIG. 12 withoutdeparting from the idea of the present disclosure all can be applied tothe following other embodiments. The following describes a single-cellbattery according to another embodiment of the present disclosure withreference to FIG. 13 to FIG. 17.

As shown in FIG. 13 to FIG. 15, an embodiment provides a single-cellbattery 1100. The single-cell battery 1100 includes a case, a batterycell accommodated in the case, an electrode terminal 1101 electricallyconnected to the battery cell, and a cover plate 1102 for sealing thecase. The electrode terminal 1101 is disposed on the cover plate 1102,to input and output currents. The single-cell battery 1100 furtherincludes a current interruption device 1200 in communication with gasinside the case. Different from the manner of being mounted on theelectrode terminal in the embodiment according to FIG. 1 to FIG. 12, thecurrent interruption device 1200 is disposed on the cover plate and isin communication with the gas inside the case. The current interruptiondevice 1200 has a conductive member 1201 and a flipping member 1202electrically connected to the conductive member 1201. The flippingmember 1202 and the conductive member 1201 can be electricallydisconnected from each other under action of air pressure. That is, theoperating principle of the current interruption device 1200 is basicallythe same as that of the current interruption device in the embodimentsaccording to FIG. 1 to FIG. 12. In both operating principles, a circuitis disconnected due to flipping of the flipping member implemented bysensing the air pressure inside the single-cell battery.

As shown in FIG. 17, because the current interruption device 1200 is notdisposed on the electrode terminal, the conductive member 1201 has abody portion 1299 connected to the flipping member 1202 and a connectingportion 1298 extending from the body portion 1299 to the electrodeterminal 1101 and connected to the electrode terminal 1101. Therefore,in this embodiment, the current interruption device 1200 is disposed onthe cover plate. This can avoid an increase in the height of theelectrode terminal 1101, thereby increasing battery capacity density byusing a length space of the cover plate.

As shown in FIG. 15 to FIG. 17, in this embodiment, the body portion1299 of the conductive member 1201 is in communication with gas insidethe case and is provided with a notch 1205. The notch 1205 is disposedaround a connection point for connecting to the flipping member 1202. Inthis way, the notch can be pulled apart under internal air pressure,thereby disconnecting the electrical connection between the flippingmember and the conductive member. Further, the notch 1205 is providedwith an air vent 1206. In this way, the air vent 1206 may be used toenable the air pressure to be applied to the flipping member 1202, andthe flipping member is used to apply tensile force to the notch. Inaddition, the notch 1205 can be easily pulled apart at a location of theair vent 1206, thereby improving sensitivity of the flipping member1202. In this case, the notch may be alternatively disposed in theflipping member. There may be multiple air vents 1206 disposed atintervals along the notch 1205. Moreover, for features of the notch, theair vent, and the like, all features in the embodiments according toFIG. 1 to FIG. 12 can be applied to this embodiment. In anotherembodiment, the body portion of the conductive member and the flippingmember may be separately provided with notches. In this way, when theair pressure inside the case increases continuously, in addition topulling apart the notch in the conductive member, the notch in theflipping member may further be pulled apart. In this case, the gasinside the battery can be discharged from the flipping member to theoutside, thereby avoiding a further increase in the air pressure insidethe case of the single-cell battery. Moreover, a gas sensor inside aninclusion body of the battery may be alternatively caused to sense analarm or disconnect a circuit. This part is to be described in detailbelow.

Specifically, the notch 1205 in the body portion can be pulled apartunder action of first air pressure inside the case, the notch in theflipping member can be pulled apart under action of second air pressureinside the case, and the second air pressure is greater than the firstair pressure. That is, strength of the notch in the body portion of theconductive member is less than strength of the notch in the flippingmember, so that the notch in the body portion of the conductive membercan be pulled apart by the smaller first air pressure. The notch in theflipping member is not further pulled apart for pressure relief unlessthe air pressure continues to increase.

In this embodiment, to ensure that the flipping member 1202 can be underaction of the air pressure inside the case, the outer periphery of theflipping member 1202 is tightly connected to the conductive member 1201,to prevent gas from leaking from the outer periphery of the flippingmember and prevent pressure relief. Specifically, the cover plate 1102is provided with an air vent in communication with gas inside the case,and the cover plate is tightly connected to a first ceramic ring 1207surrounding the air vent. The body portion 1299 is tightly connected tothe first ceramic ring 1207, so that internal air pressure can beapplied to the body portion 1299 instead of leaking to the outside.Moreover, to stably assemble the flipping member 1202, the outerperiphery of the flipping member 1202 is tightly connected to a secondceramic ring 1296, and the second ceramic ring is tightly connected tothe conductive member 1201. Therefore, with the insulation feature ofthe second ceramic ring, the outer periphery of the flipping member 1202can be stably supported, and the conductive member can be insulated fromthe outer periphery of the flipping member 1202 by using the secondceramic ring 1296. In this way, after the flipping member 1202 and theconductive member 1201 can maintain current disconnection after thenotches 1205 are pulled apart, thereby interrupting the current.

Specifically, as shown in FIG. 16 and FIG. 17, the body portion 1299 ofthe conductive member 1201 is provided with an annular boss 1297surrounding the notch 1205. In this way, with the structure of theannular boss 1297, an inner side of the annular boss 1297 in a radialdirection may be used for forming the notch 1205 and other features, anda rear concave portion of the annular boss 1297 tightly accommodates thefirst ceramic ring 1207. Moreover, an outer side of the annular boss1297 may be used to tightly support the second ceramic ring 1296. Inthis way, in this embodiment, with the unique feature of the conductivemember 1201 shown in FIG. 16 and FIG. 17, the current interruptiondevice 1200 can be more easily mounted.

Moreover, the first ceramic ring 1207 is tightly connected to the coverplate 1102 by using a transition ring 1209. As shown in FIG. 17, thetransition ring 1209 has a connecting body embedded into an inner wallof the air vent and a flange ring for connecting to the first ceramicring 1207. The flange ring protrudes from the connecting body along theradial direction and presses tightly against the cover plate. Therefore,stable mounting of the current interruption device 1200 is ensured, andthe first ceramic ring 1207 does not need to be directly connected tothe cover plate 1102.

In this embodiment, for convenience of connection, preferably, as shownin FIG. 17, the electrode terminal 1101 includes a battery post 1104passing through the cover plate 1102 and electrically connected to thebattery cell. As shown in FIG. 14 and FIG. 16, a connecting portion 1298of the conductive member 1201 is provided with a slot 1295. The batterypost 1104 penetrates the slot 1295, and the battery post 1104 is weldedto the slot 1295, so that the battery post 1104 is stably connected tothe conductive member 1201. Moreover, as shown in FIG. 15, the currentinterruption device 1200 includes a connecting member 1210 covering theflipping member 1202 and electrically connected to the flipping member1202. The connecting member 1210 has a cover portion 1294 covering theflipping member 1202 and a guide portion 1293 extending from the coverportion 1294. The connecting member 1210 may be formed in a structurethe same as that of the L-shaped connecting member 214 in the embodimentaccording to FIG. 1 to FIG. 12. That is, the cover portion and the guideportion form an L-shaped connecting member. In this way, a current canbe easily guided from the current interruption device 1200 to anadjacent electrode terminal or out of a module.

In a battery module in which at least one of the single-cell batteriesis the single-cell battery 1100, the current interruption device extendsout of the cover plate in a radial direction, thereby increasing a forcereceiving area and increasing pulling strength. Between adjacentsingle-cell batteries, the current interruption device and an adjacentelectrode terminal are staggered in a direction of extension of thecover plate 1102, to avoid affecting the structure of an adjacent coverplate. Moreover, the same as the embodiment according to FIG. 1 to FIG.12, there are a maximum of three single-cell batteries 1100 that areprovided with the current interruption device 1200.

The single-cell battery provided in the embodiments according to FIG. 13to FIG. 17 is described above, and different feature according to theembodiments of FIG. 1 to FIG. 12 are mainly described. These features ofthe embodiments may be replaced with each other or combined when thereis no contradiction. For this, details are not described herein again inthe present disclosure.

The following describes a single-cell battery 2100 according to anembodiment of the present disclosure with reference to FIG. 18. Thesingle-cell battery 2100 includes a case, a battery cell accommodated inthe case, an electrode terminal 2101 electrically connected to thebattery cell, and a cover plate 2102 for sealing the case. The electrodeterminal 2101 is disposed on the cover plate 2102. The single-cellbattery includes a first electrode guide member 2298 electricallyconnected to the battery cell, and a second electrode guide member 2297electrically connected to the electrode terminal 2101. The cover plate2102 is further provided with an explosion relief valve 2200 incommunication with gas inside the case. The explosion relief valve 2200has a flipping member 2202 connecting the first electrode guide member2298 and the second electrode guide member 2297. That is, the twoelectrode guide members are connected to each other by using theflipping member 2202.

The first electrode guide member 2298 and/or the second electrode guidemember 2297 is provided with a first notch 2205. The first notch 2205can be disconnected under action of air pressure in the case, tointerrupt a current on the first electrode guide member 2298 and/or thesecond electrode guide member 2297. That is, the first notch is used sothat the electrode guide member provided with the first notch isdisconnected, thereby stopping transmission of the current. Therefore,the battery cell and the electrode terminal can be electricallydisconnected from each other when at least one of the two electrodeguide members is provided with the first notch, thereby disconnectingcurrent transmission between the single-cell battery and the outside.Moreover, the flipping member 2202 is further provided with a secondnotch 2299. The second notch 2299 can be disconnected under action ofthe air pressure in the case, so that the gas inside the case isdischarged to the outside through the flipping member 2202. That is, thesecond notch is used for gas release. After the second notch isdisconnected, the internal gas can be discharged to the outside, therebyavoiding an explosion caused by a further increase in air pressureinside the battery, and achieving an explosion proof effect.

Specifically, the first notch can be pulled apart under action of firstair pressure inside the case, the second notch can be pulled apart underaction of second air pressure inside the case, and the second airpressure is greater than the first air pressure. That is, strength ofthe first notch 2205 is less than that of the second notch 2299, so thatthe first notch 2205 can be pulled apart by the smaller first airpressure. The second notch 2299 is not further pulled apart for pressurerelief unless the air pressure continues to increase.

As shown in FIG. 18, in this embodiment, the two electrode guide membersmay be in an elongated sheet structure, so that the current can beinterrupted. The first notch 2205 extends from an edge on one side to anedge on the other side along a width direction of the elongated sheetstructure. In this way, the elongated sheet structure can be broken in atimely manner along the first notch. The flipping member 2202 may beprovided with an annular outer wall. The two electrode guide members maybe fixedly connected to the annular outer wall, to implement currenttransmission. Specifically, in the present disclosure, the annular outerwall of the flipping member may be formed by using, for example, a bossin a boss welded structure. In addition, the flipping member is furtherformed in a conical ring structure. The conical ring obliquely extendsoutwards from the boss to an outer periphery of the flipping member, toform the flipping member in a bowl shape. Moreover, the second notch maybe formed in an annular shape around the periphery of the flippingmember, so that the second notch can be completely disconnected underaction of the air pressure, thereby improving gas pressure reliefefficiency. Specifically, the second notch may be formed in the conicalring structure. To enable the flipping member to be effectively underaction of the air pressure to pull apart the first notch and the secondnotch, the outer periphery of the flipping member 2202 is tightlyconnected to and insulated from the cover plate in a relatively fixedmanner. Therefore, on the one hand, gas can be prevented from beingdischarged to the outside when the first notch and the second notch arenot pulled apart and the two notches are not effectively used. On theother hand, the cover plate can be prevented from being electrified withinsulated connection.

In this embodiment, the electrode terminal 2101 includes a battery postpassing through the cover plate. The battery post is insulated from andconnected to an outer side of the cover plate by using the secondceramic ring, to facilitate establishment of a current loop with theoutside. That is, current transmission between adjacent single-cellbatteries is implemented with interconnection between electrodeterminals. Use of the ceramic ring can prevent the cover plate frombeing electrified. Moreover, a first ceramic ring 2207 is tightlyconnected between the outer periphery of the flipping member 2202 andthe cover plate, and is similarly used for sealing and insulation.

Moreover, to facilitate connection to the flipping member 2202, a firsttransition piece 2295 is fixedly connected to the cover plate 2102, anda second transition piece 2296 is fixedly connected to a periphery ofthe flipping member 2202. The first transition piece and the secondtransition piece may be aluminum sheets. The first transition piece 2295and the second transition piece 2296 are coaxially in brazing connectionwith the first ceramic ring 2207. In this way, during assembling, thetwo transition pieces are first welded to the first ceramic ring withbrazing, and then two fixing pieces are welded to another structure.This can avoid high temperature generated by brazing of the firstceramic ring and the structure such as the cover plate. Therefore,assembling is easily performed, the first ceramic ring 2207 is used toimplemented tight, stable, and insulated connection, and the cover plate2102 can be prevented from being electrified.

Specifically, the first transition piece 2295 and the second transitionpiece 2296 may be annular structures to fit two annular end surfaces ofthe first ceramic ring. Moreover, preferably, the cover plate 2102 isprovided with an annular boss. The first transition piece 2295 issupported in the annular boss. The first ceramic ring presses tightlyagainst an inner wall of the annular boss and extends towards the secondtransition piece 2296, so that the first ceramic ring is stablyconnected inside the cover plate 2102.

Moreover, the explosion relief valve further includes a protective film2099 that can be torn by punching by the air pressure. The protectivefilm tightly covers the flipping member 2202, and specifically, isconnected to the first transition piece 2295 away from the flippingmember. In this way, normally, the protective film 2099 can protect theinner part of the explosion relief valve 2200, and can be torn bypunching by certain air pressure, for example, second air pressure, whenexplosion proof is required, thereby avoiding impact on an explosionproof effect of the explosion relief valve.

Moreover, in the present disclosure, in order that the two notches aresequentially pulled apart, a ratio of a residual thickness of the firstnotch to a residual thickness of the second notch is 1:3 to 1:1.2, andfurther, is 1:2 to 1:1.3.

The following describes an embodiment according to the presentdisclosure with reference to FIG. 22 and FIG. 23.

This embodiment provides a single-cell battery 3100 and a battery moduleusing the single-cell battery. The single-cell battery 3100 includes acase, a battery cell accommodated in the case, a cover plate 3102 forsealing the case, and an electrode terminal 3101 disposed on the coverplate 3102. The single-cell battery 3100 further includes an internalguide member 3299 electrically connected to the battery cell and acurrent interruption device 3200 connected between the internal guidemember 3299 and the electrode terminal 3101. Different from the mannerof being mounted on the outer end of the battery post in the embodimentsaccording to FIG. 1 to FIG. 12, the current interruption device 3200 inthis embodiment is located at the inner side of the cover plate 3102 andis in communication with gas inside the case, to be capable ofinterrupting, under action of air pressure, a current flowing throughthe current interruption device 3200. An adaptor portion 3298 extendingoutwards from an outer periphery along a radial direction is connectedto the electrode terminal 3101, so that the electrode terminal 3101 isconnected to the outer periphery of the current interruption device byusing the adaptor portion 3298.

In this way, the adaptor portion 3298 extending outwards from the outerperiphery of the electrode terminal in the radial direction is used, sothat compared with a manner of being directly connected to the electrodeterminal, an area of the current interruption device whose outer side isconnected to the adaptor portion 3298 in the radial direction can bedesigned larger, thereby increasing an area in which the internal airpressure applies force to the current interruption device. In this way,force received by the current interruption device can be increased whilethe air pressure remains unchanged, thereby improving sensitivity of thecurrent interruption device 3200, and implementing a current interruptin timely manner. Particularly, when the battery of the presentdisclosure is applied in the field of large batteries such as powerbatteries, a high current usually needs to be transmitted. Therefore,addition of the adaptor portion and enlarging the size of the currentinterruption device can both facilitate transmission of the highcurrent.

In this embodiment, the adaptor portion 3298 is formed in an annularstructure. An inner periphery of the annular structure is connected tothe outer periphery of the electrode terminal, and the outer peripheryis connected to the outer periphery of the current interruption device,so that the area of the current interruption device is increased. Inanother embodiment, the adaptor portion 3298 may alternatively be astructure of multiple connection posts extending along the radialdirection and disposed at intervals along a circumferential direction.This can also increase the area of the current interruption device.

In this embodiment, to increase tightness of the adaptor portion withthe electrode terminal and the current interruption device, and ensurestable current transmission, preferably, the inner periphery of theannular structure fits a rabbet in an outer periphery of an inner end ofthe electrode terminal. Specifically, the outer periphery of the innerend of the electrode terminal is provided with a rabbet, and the innerperiphery of the adaptor portion is embedded into and connected to therabbet. In this way, a connection area is increased, so that currenttransmission efficiency is improved while stability of the connection isensured. Inner and outer ends of the electrode terminal are definedrelative to the case along an axial direction of the electrode terminal.That is, an end close to the inner part of the case is the inner end.

Moreover, in this embodiment, the outer periphery of the annularstructure protrudes inwards the case. That is, the annular structure isformed in an annular cap structure, and the current interruption devicefits the rabbet at the inner side of the outer periphery. This not onlyensures stability of the connection and improves the currenttransmission efficiency, but also can space the current interruptiondevice and the electrode terminal, thereby providing space fordisconnecting the current interruption device under action of the airpressure.

In this embodiment, the internal guide member 3299 includes a connectingpiece (not shown) connected to the battery cell. The connecting pieceextends towards the cover plate from the battery cell. Moreover, theinternal guide member further includes a support groove foraccommodating and mounting the current interruption device, andconnecting plates extending towards opposite directions from the supportgroove. The connecting plates are separately in insulated connectionwith the cover plate, thereby preventing the cover plate from beingelectrified. Specifically, the connecting plates and a connecting groovemay form an integral sheet-like structure. That is, the connectinggroove includes two side walls and one bottom wall. The two side wallsare respectively connected to the connecting plates at two sides.Moreover, to cause the current interruption device to be incommunication with the gas inside the case, the bottom wall of thesupport groove may be designed to be provided with an air passing holein communication with the gas inside the case.

In this embodiment, to prevent the cover plate from being electrified,the internal guide member 3299 is in insulated connection with the innerside of the cover plate 3102 by using a ceramic member 3296.Specifically, the ceramic member 3296 may be formed as a ceramic sheet,and is in welded connection with the internal guide member 3299 and thecover plate by using transition pieces 3294. That is, there are twotransition pieces 3294. The transition pieces may be aluminum sheets,located separately on upper and lower surfaces of the ceramic member3296. The ceramic member 3296 is in welded connection with the coverplate 3102 by using the transition piece 3294 located on the uppersurface of the ceramic member 3296. In addition, the ceramic member 3296is further in welded connection with the internal guide member 3299 byusing the transition piece 3294 located on the lower surface of theceramic member 3296. In this way, welded connection between the ceramicmember 3296 and the cover plate 3102 and between the ceramic member 3296and the internal guide member 3299 are more easily implemented, and thewelded structure is stable. The ceramic member 3296 may be connected tothe transition pieces 3294 located on the upper and lower surfaces ofthe ceramic member 3296 with ceramic brazing. The transition piece 3294located on the upper surface of the ceramic member 3296 may be connectedto the cover plate 3102 with laser welding. The transition piece 3294located on the lower surface of the ceramic member 3296 may be connectedto the internal guide member 3299 with laser welding.

In this embodiment, the current interruption device 3200 has aconductive member 3201 and a flipping member 3202 connected to theconductive member 3201 for mutual electrical connection. In addition,the flipping member 3202 and the conductive member 3201 can beelectrically disconnected from each other under action or air pressure.The conductive member 3201 is connected to the internal guide member3299 and is provided with an air-guide hole 3213 in communication withgas inside the case. Specifically, the conductive member 3201 isembedded in and connected to a support groove of the internal guidemember. In this way, an air passing hole formed in the support groovemay be in gas communication with the air-guide hole 3213, so that theflipping member 3202 can feel pressure applied by the gas inside thecase, thereby disconnecting the electrical connection between theflipping member 3202 and the conductive member 3201 under action ofinternal air pressure. An outer periphery of the flipping member 3202and an outer periphery of the adaptor portion 3298 are connected to eachother to establish a current connection path.

In this embodiment, in a manner of disconnecting the electricalconnection, the conductive member 3201 is provided with a notch, and thenotch is disposed surrounding a connection point for connecting to theflipping member 3202. In this way, under action of the internal airpressure, the notch is pulled apart, thereby disconnecting theelectrical connection between the conductive member and the flippingmember. In another embodiment, the notch may alternatively be formed inthe flipping member or a manner of pulling apart a connection pointbetween the two may be used. To apply the air pressure to the flippingmember 3202, the outer periphery of the flipping member 3202 is insupporting connection with the conductive member 3201 and/or theinternal guide member 3299 by using an insulation member 3295, therebyimplementing assembling of the flipping member 3202 by using theinsulation member 3295. This can ensure that the outer periphery of theflipping member is insulated from the internal guide member 3299 and theconductive member, thereby preventing the flipping member from stillbeing electrically connected to the conductive member or the internalguide member at the outer periphery after the flipping member iselectrically disconnected from the conductive member under action of theair pressure.

Specifically, the insulation member may be an annular insulation membersuch as a ceramic ring or a sealing ring. There are three connectionmanners for the insulation member. In a first manner, the insulationmember tightly supports the conductive member 3201, and specifically,supports a region in the conductive member 3201 that surrounds a regionthat is pulled apart. In a second manner, the insulation member supportsthe internal guide member 3299, and specifically, supports a region ofthe internal guide member 3299 that surrounds the conductive member3201. In a third manner, the insulation member supports both theinternal guide member 3299 and the conductive member 3201. That is, asshown in FIG. 23, the insulation member supports a region connecting theinternal guide member 3299 and the conductive member 3201.

To ensure stable current transmission between the conductive member andthe flipping member, especially, to be applicable to a high-currentpower battery, similar to the embodiments according to FIG. 1 to FIG.12, if the conductive member is provided with a notch 3205, as shown inFIG. 23, the flipping member 3202 and the conductive member 3201 areconnected to each other by using a boss welded structure surrounded bythe notch 3205. The boss welded structure includes a boss 3203, aconnection hole 3204 accommodating the boss 3203, and an annular weldingspot 3217 located between the boss 3203 and the connection hole 3204,thereby ensuring effective passing of a high current. Specifically, asshown in FIG. 23, different from what is shown in FIG. 6, the boss 3203is formed in the flipping member 3202 while the connection hole 3204 isformed in the conductive member 3201. In addition, alternatively, a casethat is the same as FIG. 6 may be used, that is, the boss is formed inthe conductive member 3201, and the connection hole 3204 is formed inthe flipping member.

Moreover, as shown in FIG. 22, the conductive member 3201 may be formedin a cap-shaped structure. The cap-shaped structure includes a cap bodyconnected to the flipping member and a cap brim surrounding the capbody. The cap brim is provided with the air-guide hole and is connectedto the internal guide member. The cap body protrudes towards theflipping member. The flipping member is formed in a sheet-likestructure, and the insulation member 3295 is connected between an outerperiphery of the sheet-like structure and the cap brim. Therefore, thestructure of the current interruption device provided in the presentdisclosure is compact, and assembling is stable.

In this embodiment, to establish a current loop to the outside,preferably, the electrode terminal 3101 includes a battery post 3104passing through the cover plate. The battery post is in insulatedconnection with the cover plate by using the ceramic ring 3293, therebypreventing the cover plate from being electrified. Moreover, the adaptorportion 3298 is connected to an inner end of the battery post toestablish a current loop to the outside by using a part protruding outof the cover plate. Specifically, the ceramic ring 3293 is tightlyconnected to an outer surface of the cover plate and is tightlyconnected to the battery post 3104, to ensure a sealing effect insidethe cover plate. An air hole 3292 is formed through the battery postalong an axial direction. In this way, in a process of disconnectionunder pressure, the current interruption device 3200 is not affected byair pressure of a closed cavity in the cover plate but can have apressure difference with the outside atmospheric air, so that theflipping member 3202 can make a movement under action of the pressuredifference between the internal pressure and the external pressure topull the notch 3205 apart.

The single-cell battery provided in the embodiments according to FIG. 22and FIG. 23 is described above. The following describes an embodiment ofthe present disclosure with reference to FIG. 24.

This embodiment provides a single-cell battery 4100 and a battery moduleusing the single-cell battery. The single-cell battery 4100 includes acase, a battery cell accommodated in the case, an electrode terminal4101 electrically connected to the battery cell, and a cover plate 4102for sealing the case. The electrode terminal 4101 is disposed on thecover plate 4102. The electrode terminal includes a battery post 4104passing through the cover plate 4102 and electrically connected to thebattery cell by using an internal guide member 4196. The single-cellbattery further includes a current interruption device 4200 mounted onthe battery post 4104. The current interruption device 4200 has aflipping member 4202 that is fixed relative to the cover plate 4102 andthat is in communication with gas inside the case. In addition, theflipping member 4202 is connected to an outer end surface of the batterypost 4104 by using a connection point. The connection point can bedisconnected under action of air pressure. In this way, the operatingprinciple of the current interruption device in this implementation isto directly separate the flipping member 4202 from the battery post 4104at the connection point with the air pressure, thereby disconnecting theelectrical connection between the flipping member 4202 and the batterypost 4104.

To improve sensitivity, preferably, the flipping member 4202 isconnected to the battery post by using a single welding spot 4199. Forexample, the welding spot 4199 created with spot welding is used. Inaddition, another welding means such as laser welding may be used forimplementation. Therefore, in this implementation, weld penetration andweld width of the welding spot are properly set, to control tensilepressure.

In this implementation, similar to the embodiments according to FIG. 1to FIG. 12, the battery post 4104 is provided with an air-guide hole4103 in communication with the inner part of the case, so that theinternal air pressure can be easily guided to the current interruptiondevice. Moreover, to further improve reliability of the currentinterruption device, preferably, the flipping member 4202 is providedwith a notch 4205. The notch 4205 is disposed surrounding a connectionpoint. In this way, in addition to pulling apart the connection point,pulling the notch 4205 apart may also be used to interrupt a current. Inthis implementation, the air pressure for pulling apart the connectionpoint is different from air pressure for pulling apart the notch.Specifically, the connection point can be pulled apart under action offirst air pressure inside the case, and the notch 4205 can be pulledapart under action of second air pressure. The second air pressure isgreater than the first air pressure. In this way, the notch 4205 can beused as a backup measure of the connection point, to ensure batterysafety. More preferably, the flipping member 4202 is covered by acovering cap 4210. The covering cap 4210 is provided with an air hole4197. In this way, after the notch 4205 is pulled apart, the gas insidethe case passes through the flipping member and is then discharged fromthe air hole 4197, thereby implementing pressure relief inside thebattery, and preventing explosions inside the battery. This principle issimilar to that of the explosion relief valve in the embodimentaccording to FIG. 18.

In this implementation, a first ceramic ring 4207 is connected betweenthe battery post 4104 and the cover plate 4102, so that the battery postis stably mounted by using the ceramic structure and the cover plate4102 is prevented from being electrified. Moreover, a second ceramicring 4198 is tightly connected between the battery post 4104 and anouter periphery of the flipping member, so that the outer periphery ofthe flipping member can be sealed by using the ceramic structure,thereby ensuring that the internal gas can effectively apply pressure tothe flipping member and that the battery post is insulated from theouter periphery of the flipping member, and preventing the flippingmember from being still conductive after the connection point or thenotch is pulled apart.

Specifically, in an embodiment, the battery post 4104 has an annularboss 4297 surrounding the connection point. The first ceramic ring 4207is tightly accommodated in a rear concave portion of the annular boss4297. The first ceramic ring 4207 is tightly connected to the coverplate 4102. A radial outer side of the annular boss 4297 tightlysupports the second ceramic ring 4198. The second ceramic ring 4198tightly supports the outer periphery of the flipping member 4202. Inthis way, the overall structure of the current interruption device ismore compact, and the assembling is stable. For ease of assembly, thefirst ceramic ring 4207 is tightly connected to the cover plate 4102 byusing a transition ring 4209. Specifically, ceramic brazing may beperformed on the transition ring and the first ceramic ring 4207 for thetight connection.

The following describes an embodiment of the present disclosure withreference to FIG. 5 to FIG. 7, FIG. 20, and FIG. 21. This embodimentprovides a single-cell battery and a battery module. Effects of featuresthat are the same as those in the foregoing embodiments are notdescribed in detail herein again.

This embodiment provides a single-cell battery. The single-cell battery100 includes a case 109, a battery cell 108 accommodated in the case109, an electrode terminal 101 electrically connected to the batterycell 108, and a cover plate 102 for sealing the case. The electrodeterminal 101 is disposed on the cover plate 102. The electrode terminalincludes a battery post 104″′ passing through the cover plate 102 andelectrically connected to the battery cell. The single-cell batteryfurther includes a current interruption device 200 mounted on thebattery post 104″′. The current interruption device 200 is incommunication with gas inside the case. The current interruption device200 has a conductive member 201 and a flipping member 202 connected tothe conductive member 201 for mutual electrical connection. In addition,the flipping member 202 and the conductive member 201 can beelectrically disconnected from each other under action of air pressure.The conductive member 201 is connected to the battery post 104″′ formutual electrical connection. The flipping member 202 and the conductivemember 201 are connected to each other by using a boss welded structure.The boss welded structure includes a boss 203, a connection hole 204accommodating the boss 203, and an annular welding spot 217 locatedbetween the boss 203 and the connection hole 204. The flipping member202 is formed in a first sheet-like structure. The first sheet-likestructure is provided with the connection hole 204. The conductivemember 201 is formed in a second sheet-like structure. The secondsheet-like structure is provided with the boss 203. The conductivemember 201 is provided with a notch 205. The notch 205 is disposedsurrounding the boss 203. The conductive member 201 is connected to anouter end surface of the battery post 104′″. An outer periphery of theflipping member 202 is fixed relative to the cover plate 102. Thebattery post 104′″ is fixedly connected to the cover plate 102, and thebattery post 104′″ is provided with an air-guide duct communicating aninner part of the case and the current interruption device 200. Thebattery post 104′″ is mounted in a ceramic ring 207″ tightly connectedto the cover plate 102. An outer end surface of the ceramic ring 207″ istightly connected to a conductive ring 216′. The outer periphery of theflipping member 202 is tightly connected to the conductive ring 216′.The battery post 104′″ and the conductive ring 216′ are insulted byusing the ceramic ring 207″. In this way, a current is stablytransmitted or interrupted.

In this embodiment, the outer end surface of the battery post 104′″ isprovided with an accommodation hole 218′, and an outer periphery of theconductive member 201 is fixed to an inner wall of the accommodationhole.

In this embodiment, the notch 205 is elliptical, the boss 203 iscircular, a center of the notch 205 and a center of the boss 203 arestaggered along a direction of major axis of the ellipse, and the majoraxis of the ellipse and an axial line of the electrode terminal areobliquely disposed.

In this embodiment, in addition, an outer end periphery of the batterypost 104′″ has a radial boss 105″. An inner periphery of the ceramicring 207″ has a radial support 208″ supporting and connected to theradial boss 105″. There are multiple radial bosses 105″ disposed atintervals along a circumferential direction. There are multiple radialsupports 208″ disposed at intervals along the circumferential direction.The multiple radial bosses are in a one-to-one correspondence with themultiple radial supports.

In this embodiment, the outer end surface of the ceramic ring 207″ isformed in a stepped structure having an inner ring and an outer ring.The battery post 104′″ is in embedded connection with the inner ring.The outer ring is tightly connected to the conductive ring 216′insulated from the battery post 104′″. The outer periphery of theflipping member 202 is fixedly connected to the conductive ring 216′. Aninner end surface of the ceramic ring 207″ is tightly connected to atransition ring 209′. The transition ring 209′ is tightly connected tothe cover plate 102 so that the ceramic ring 207″ and the cover plate102 are disposed at intervals.

In this embodiment, the ceramic ring 207″ is tightly connected to theconductive ring 216′, the battery post 104′″, and the transition ring209′ with ceramic brazing.

In this embodiment, the transition ring 209′ has an inner ring and anouter ring that form a Z-shaped structure. The cover plate is providedwith a through hole through which the battery post 104 passes. An endsurface of the through hole is in a staircase structure. The inner ringof the transition ring is embedded in and supports the staircasestructure.

In this embodiment, the outer end surface of the conductive ring 216′ isprovided with an L-shaped rabbet. The outer periphery of the flippingmember 202 is embedded in and supports the L-shaped rabbet. The outerperiphery is tightly connected to the L-shaped rabbet by using acovering cap 210 covering the flipping member 202.

To implement assembling of the single-cell battery, as shown in FIG. 20and FIG. 21, a lower spacer ring 107 is connected to the battery cell108, and an upper spacer ring 106 is connected below the cover plate102. The upper and lower spacer rings may be made of an insulatingmaterial. The single-cell battery 100 further includes an internalconnecting sheet 110 connected to the battery cell. The internalconnecting sheet 110 extends to between the upper spacer ring 107 andthe lower spacer ring 106. A lower surface of the battery post 104′″ isprovided with a staircase portion. The staircase portion passes throughthe cover plate 102 and the upper spacer ring 106 and is clipped to anend portion of the internal connecting sheet 110. In this way, thecurrent is transmitted from the battery cell 108 to the battery post104″, and the cover plate 102 is insulated from the case 109 andprevented from being electrified.

According to a battery module provided in this embodiment, the batterymodule includes multiple single-cell batteries. At least one of thesingle-cell batteries is the single-cell battery described above. Thecurrent interruption device 200 extends out of the cover plate 102 alonga radial direction. Between adjacent single-cell batteries 100, thecurrent interruption device 200 and an adjacent electrode terminal arestaggered in a direction of extension of the cover plate. Moreover, asshown in FIG. 1, between the adjacent single-cell batteries 100, thecurrent interruption device 200 is connected to the adjacent electrodeterminal by using an L-shaped connecting member 214. The L-shapedconnecting member 214 has a cover portion 211 and a guide portion 212.The cover portion 211 covers and is connected to the currentinterruption device 200. The guide portion 212 extends to the adjacentelectrode terminal.

In addition, this embodiment further provides a power battery. The powerbattery includes an inclusion body and a battery module accommodated inthe inclusion body. The battery module is the battery module describedabove. A gas detection device for detecting flammable gas is disposedinside the inclusion body. The gas detection device is disposed close tothe current interruption device, to provide a flammable gas signal for acharge/discharge protection system. Moreover, considering costs and theeffect, the battery module needs to have only one current interruptiondevice.

The single-cell battery having a current interruption device or anexplosion relief valve is described above. The current interruptiondevice or the explosion relief valve each implements safety measures byusing a mechanical structure of the current interruption device or theexplosion relief valve. The following describes in detail a powerbattery including a charge/discharge protection system, to improvesafety with electrical control.

As shown in FIG. 19, the present disclosure provides a power battery.The power battery may be a power battery having a current interruptiondevice or an explosion relief valve, or another type of power battery.The power battery includes an inclusion body and multiple single-cellbatteries 100 accommodated in the inclusion body. For example, themultiple single-cell batteries 100 may be connected in series or inparallel to form a battery module. A gas detection device 300, forexample, a gas sensor, for detecting flammable gas in the power batteryis disposed inside the inclusion body, to provide a signal forindicating whether to switch off a charge/discharge circuit of the powerbattery.

In addition to including the gas detection device 300 located inside thepower battery, the charge/discharge protection system included in thepower battery further includes a control device 400 and a circuitswitching on/off device.

The gas detection device 300 feeds back a flammable gas signal to thecontrol device 400. The control device 400 is configured to control,according to the flammable gas signal, the circuit switching on/offdevice to switch off the charge/discharge circuit of the power batterycontrol. That is, safety of the present disclosure is automatic controlperformed by detecting whether there is flammable gas in the inclusionbody. In an emergency state such as overcharging of the battery,flammable gas is produced inside the battery. The part of gas more orless leaks to the inner part of the inclusion body in various manners.In this case, the gas detection device, for example, the gas sensor, candetect the flammable gas, and feeds back such information to the controldevice. The control device determines, according to whether flammablegas is detected or an amount of detected flammable gas, whether todisconnect the charge/discharge circuit of the power battery. Whenflammable gas is detected, or an amount of flammable gas exceeds apreset threshold, the circuit switching on/off device may be controlledto disconnect the charge/discharge circuit of the power battery, ensuresafety of the power battery.

To further reduce potential risks, the power battery further includes analarm device 500 controlled by the control device 400. In this way,relevant personnel may be instructed, with voice, flash, or a alarmdevice such as a siren, to evacuate the site, thereby reducing potentialrisks.

As shown in FIG. 19, the control device 400 includes a host computermain control chip 401 of the power battery and a control module 402 insignal connection with the main control chip. The control module 402 isin signal connection with the circuit switching on/off device. Thecircuit switching on/off device may be a relay 403 located in thecharge/discharge circuit, to be controlled by the control module 402 toswitch off the charge/discharge circuit. Moreover, the alarm device 500may be in signal connection with the host computer control chip 401, toreceive an alarm from an alarm instruction.

In a specific operating process, digital-to-analog conversion, sampledstorage, and other processing may be performed on an acquired signal ofthe gas sensor. Moreover, fault detection may further be performed onthe system. When no failure occurs in the system, gas concentrationprocessing may further be performed on the acquired signal, to determinewhether leakage of flammable gas occurs. When the concentration of theleakage of the flammable gas exceeds a threshold, the host computer maincontrol chip 401 performs operations of interrupting the current andalarming.

In this implementation, the gas detection device is disposed outside thesingle-cell battery. The flammable gas may be discharged to the outsideby pulling apart the notch in the current interruption device or theexplosion relief valve. In addition, various known conventionalexplosion relief valves may be used to discharge the gas to the outsideprovided that the valves are capable of discharging the gas to theoutside. That is, in the battery module, at least one of the single-cellbatteries is provided with a current interruption device fordisconnecting the charge/discharge circuit under action of gas pressureinside the single-cell battery, that is, the foregoing currentinterruption device. In addition, the current interruption device canenable gas inside a case to be discharged to the outside in adisconnected state. In this way, the gas detection device in theinclusion body can detect the flammable gas discharged to the outside.In this case, it indicates that an emergency case of overcharging of thebattery occurs. In addition, to improve sensitivity of the system,preferably, the gas detection device is disposed close to the currentinterruption device, so that the gas detection device can detect acorresponding signal in a timely manner after the flammable gas isreleased, and feeds back the signal to the control device. Moreover, inaddition to the current interruption device, in some implementations, atleast one of the single-cell batteries is provided with an explosionrelief valve capable of discharging gas under action of gas pressureinside the single-cell battery, for example, the explosion relief valvein the embodiment according to FIG. 18. In this case, the gas detectiondevice may be disposed close to the explosion relief valve.

To discharge the gas to the outside, the current interruption device ineach of the foregoing implementations is provided with a cover member.The cover member is provided with an air hole so that the gas inside thecase can be discharged to the outside after the flipping member and aconductive member are electrically disconnected from each other.Moreover, the air hole in the cover member may further enable thecurrent interruption device to have a pressure difference with theatmospheric air, so that an action of the flipping member isimplemented. The cover member herein may be the covering cap 210 in theembodiments according to FIG. 1 to FIG. 12, or may be the connectingmember 1210 in the embodiments according to FIG. 13 to FIG. 17, or theprotective film 2099 in the embodiment according to FIG. 18, or thelike. In this way, after the corresponding notch is pulled apart, thegas can be discharged to the outside by using, for example, the air hole213 in the embodiments according to FIG. 1 to FIG. 12, so that the gasdetection device can detect in a timely manner flammable gas that leaksto the pack.

Moreover, the air hole in the cover member may further enable thecurrent interruption device to have a pressure difference with theatmospheric air, so that an action of the flipping member isimplemented. The cover member herein may be the covering cap 210 in theembodiments according to FIG. 1 to FIG. 12, or may be the connectingmember 1210 in the embodiments according to FIG. 13 to FIG. 17, or theprotective film 2099 in the embodiment according to FIG. 18, or thelike. In this way, after the corresponding notch is pulled apart, thegas can be discharged to the outside by using, for example, the air hole213 in the embodiments according to FIG. 1 to FIG. 12, so that the gasdetection device can detect in a timely manner flammable gas that leaksto the pack.

The embodiments of the present disclosure are described in detail withreference to the accompanying drawings. However, the present disclosureis not limited to the specific details in the foregoing embodiments.Various simple variations may be made to the technical solutions of thepresent disclosure within the technical idea of the present disclosure.These simple variations all fall within the protection scope of thepresent disclosure.

Moreover, it should be noted that, the specific technical featuresdescribed in the foregoing specific embodiments may be combined in anyappropriate manner when there is no contradiction. To avoid unnecessaryrepetitions, possible combination manners are not additionally describedin the present disclosure.

In addition, the different embodiments of the present disclosure may berandomly combined, and the combinations may also be considered ascontent disclosed by the present disclosure provided that thecombinations do not depart from the idea of the present disclosure.

Finally, the research and development background for introducing theforegoing inventive ideas of the present disclosure are described.

Environmental pollution increasingly deteriorates, development of newenergy vehicles become a new national strategic plan. Currently,all-electric vehicles and plug-in hybrid vehicles of the new energyvehicles dominate the automobile market. In the field of electricvehicles, the endurance mileage is a main factor restricting thedevelopment of the electric vehicles, and the endurance mileage dependson energy density of a battery cell. Currently, there are mainly twomaterials: a ternary material and Lithium iron phosphate for batterycells in the market. Although with high energy density, the ternarymaterial is poor in safety performance. Particularly, overchargingcauses fires or explosions. This is a great challenge for the automotiveindustry having strict requirements on safety performance.

As a greater battery capacity leads to better endurance mileage, somesolutions to improvement of the safety performance of the ternarymaterial need to be used to ensure safety of the ternary. However,because it is difficult to further improve the performance of thematerial, a solution relating to structures needs to be considered.

As described in the related art, in the existing design of a batterypack, a BMS is mainly used to perform voltage and current temperaturemanagement and control on a battery cell in a module. However, in anactual use process, there are still incidental risks of consistency ofthe battery cell and reliability of management software. Specifically,referring to people's usage habits with regard to mobile devices, thepeople usually plug in car bodies to recharge the electric vehicles allthe time. Because the BMS software is used to control the recharging,such batteries are merely recharged for a long time. However, ifsoftware detection fails or another exception occurs, a risk ofovercharging of a battery cell in a loop in an inclusion body occurs.Therefore, the author of the present disclosure conceives of a designfor providing mechanical protection for a battery, to prevent a batterysafety risk from occurring after a software failure.

For mechanical protective measures, the author of the present disclosurecreatively finds that there is a law of current interruption timing of abattery in an emergency state such as overcharging. To be specific, acurrent interruption device or an explosion relief valve capable ofinterrupting a current on an electrode terminal can be designedaccording to the principle that internal air pressure increases in anemergency state such as overcharging. In this way, inputting oroutputting through the electrode terminal can be controlled, therebyensuring safety.

Moreover, a capacity of a power battery used in an automobile is usuallyten-odd times of that of a 3C battery, and a through current the powerbattery is dozens or even hundreds of times of that of a minor class ofbattery. Therefore, the power battery further needs to withstand a veryhigh through current. In addition, requirements on weather resistanceand leak tightness of the power battery are stricter because of a usageenvironment. These problems are collected and then the technicalsolutions of the present disclosure are formed. In addition, as verifiedby tests, the current interruption device or the explosion relief valvein any of the implementations of the present disclosure can interrupt acurrent in a battery in a timely manner, thereby effectively improvingsafety.

What is claimed is:
 1. A single-cell battery, comprising: a case; abattery cell accommodated in the case; an electrode terminalelectrically connected to the battery cell; a cover plate for sealingthe case, wherein the electrode terminal is disposed on the cover plate,and the electrode terminal comprises a battery post passing through thecover plate and electrically connected to the battery cell; and acurrent interruption device mounted on an outer end of the battery postoutside of the case and in communication with gas inside the case,comprising a conductive member and a flipping member, wherein theflipping member is connected to the conductive member, the flippingmember and the conductive member are electrically disconnected from eachother under an action of air pressure, and the conductive member isconnected to the battery post, and the conductive member is connected toan outer end surface of the battery post, and an outer periphery of theflipping member is fixed with respect to the cover plate.
 2. Thesingle-cell battery according to claim 1, wherein the flipping memberand the conductive member are connected to each other by using a bosswelded structure, the boss welded structure comprises a boss, aconnection hole accommodating the boss, and an annular welding spotlocated between the boss and the connection hole.
 3. The single-cellbattery according to claim 2, wherein the flipping member is formed in afirst sheet-like structure, the first sheet-like structure includes theconnection hole, the conductive member is formed in a second sheet-likestructure, and the second sheet-like structure includes the boss.
 4. Thesingle-cell battery according to claim 1, wherein the conductive memberincludes a notch, and the notch is disposed surrounding a connectionpoint for connecting to the flipping member.
 5. The single-cell batteryaccording to claim 4, wherein the notch has a shape of ellipse, theconnection point is a circular connection point, and a center of thenotch and a center of the connection point are staggered along adirection of major axis of the ellipse.
 6. The single-cell batteryaccording to claim 4, wherein the flipping member and the electrodeterminal are coaxially disposed, and the conductive member is obliquelydisposed relative to an axial line of the electrode terminal.
 7. Thesingle-cell battery according to claim 1, wherein the outer end surfaceof the battery post includes an accommodation hole, and an outerperiphery of the conductive member is fixed to an inner wall of theaccommodation hole.
 8. The single-cell battery according to claim 1,wherein the battery post is mounted in a ceramic ring connected to thecover plate.
 9. The single-cell battery according to claim 8, wherein aninner end surface of the ceramic ring is connected to a transition ring,and the transition ring is connected to the cover plate so that theceramic ring and the cover plate are disposed at intervals.
 10. Abattery module comprising a single-cell battery, wherein the single-cellbattery comprises: a case; a battery cell accommodated in the case; anelectrode terminal electrically connected to the battery cell; a coverplate for sealing the case, wherein the electrode terminal is disposedon the cover plate, and the electrode terminal comprises a battery postpassing through the cover plate and electrically connected to thebattery cell; and a current interruption device mounted on an outer endof the battery post outside of the case and in communication with gasinside the case, comprising a conductive member and a flipping member,wherein: the flipping member is connected to the conductive member, theflipping member and the conductive member are electrically disconnectedfrom each other under an action of air pressure, and the conductivemember is connected to the battery post, and the conductive member isconnected to an outer end surface of the battery post, and an outerperiphery of the flipping member is fixed with respect to the coverplate.
 11. A power battery, comprising an inclusion body and a batterymodule disposed inside the inclusion body, wherein the battery module isthe battery module according to claim
 10. 12. An electric vehicle,wherein the electric vehicle includes the power battery according toclaim 11.